METHOD FOR MANUFACTURING A TOOL HANDLE
The present invention relates to a method for manu¬ facturing a tool handle which is designed especially for holding a cutting tip of sintered carbide or the like and which has a substantially circular cross section throughout a considerable portion of its length, but which is provided with at least one part projecting from said cross section.
Hitherto, the manufacture of such tool handles has set out from a bar stock the cross section of which contains the dimensions of both the handle and the pro¬ jecting part. This has entailed a substantial waste of material and extensive processing efforts. These drawbacks are overcome by the method of the present invention which is characterised by deforming a bar stock having the circular cross section of the tool handle in such a manner that there is formed a protroduing portion containing the dimensions of said projecting part, and thereafter processing the bar stock in a manner to produce the tool handle having said projecting part. Thus, the invention makes it possible to minimize the consumption of material and at the same time to sub¬ stantially reduce the processing efforts.
The invention will be described in greater detail hereinbelow with reference to the accompanying drawings showing, by way of example only, three embodiments there¬ of. Figs. 1-6 illustrate the first embodiment. Figs. 1, 3 and 5 are side views of three consecutive processing stages, while Figs. 2, 4 and 6 show the bar stock from one end at the respective processing stage. Figs. 7-12 show the second embodiment. Figs. 7 and 8 show the bar stock before processing, Fig. 7 being a side view and Fig. 8 an end view. Fig. 9 shows the swaging operation from the side, while Fig. 10 shows the bar stock from one end thereof after swaging. Fig. 11 is a side view
of the finished tool handle, while Fig. 12 shows the same from one end thereof. Figs. 13 and 14 show the third embodiment in which the projecting part differs substantially from that of the two previous embodiments. Fig. 13 shows the end portion of the tool handle as seen from above, while Fig. 14 shows said portion as seen from the end.
In the drawings, a bar stock having the circular cross section of the finished tool handle 6 is designated 1. Since the finished tool handle 6 should be provided with the projecting part 2 which is shown in Figs. 5 and 6 and which in a per se known manner should carry the cutting tip 3 , the bar stock end portion 4 whose initial position is indicated by dashed lines in Fig. 1, is so bent as to form the protruding portion 5. The portion 5 contains the dimensions of the projecting part 2. After bending, which is effected according to circumstances in the cold or the heated state, the bar stock 1 is so processed as to produce the tool handle 6 with the projecting part 2. As shown in Figs. 3 and
4, the bent end portion 4 of the bar stock 1 is subjected to turning, whereby a projecting part 2' is formed. The part 2 ' has such a shape that it can be formed into a part 2 projecting either to the left or to the right, one of which is shown in Figs. 5 and 6. After a few milling operations, the tool handle 6 is given its final shape as shown in Figs. 5 and 6.
As appears from Figs. 7 and 8, the bar stock 11 in the second embodiment consists of a bar of circular cross section. Before the bar 11 is swaged in the tool 12, consisting of a movable punch 13 and a die 14, that end of the bar 11 which is to be engaged by the tool
12 is heated. Swaging is effected by moving the punch
13 from the position indicated by dash-dot lines to the position indicated in full lines. This gives rise to the protruding portion 15 which thus contains the dimensions of the projecting part 16. After annealing
the tool handle 17 is given its final shape, as shown in Figs. 11 and 12, by turning and milling operations. In connection with the swaging, other parts 18 of the bar stock 11 can be given substantially their final shape, this minimizing the final operations.
As appears from the two embodiments described above, the projecting parts 2 and 16 are narrow and oriented at right angles to the axes of the tool handles 6 and 17. It goes without saying that the projecting parts may be oriented otherwise. The embodiment in Figs. 13 and 14 shows that the projecting part 21 may have a completely different shape. In this embodiment, the end of the bar stock 22 is thus bent in substantially the same manner as in Fig. 1. The end is thereafter subjected to a milling operation, such that a seat 23 for the cutting tip 24 is formed in the finished tool handle 25.
The invention is not restricted to that described above and shown in the drawings, but may be modified in several different ways within the spirit and scope of the accompanying claims.